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Diffstat (limited to 'static/freebsd/man4/virtio.4')
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diff --git a/static/freebsd/man4/virtio.4 b/static/freebsd/man4/virtio.4 new file mode 100644 index 00000000..6af6300b --- /dev/null +++ b/static/freebsd/man4/virtio.4 @@ -0,0 +1,134 @@ +.\" Copyright (c) 2011 Bryan Venteicher +.\" All rights reserved. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND +.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE +.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS +.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +.\" SUCH DAMAGE. +.\" +.Dd April 4, 2026 +.Dt VIRTIO 4 +.Os +.Sh NAME +.Nm virtio +.Nd VirtIO Device Support +.Sh SYNOPSIS +To compile VirtIO device support into the kernel, place the following lines +in your kernel configuration file: +.Bd -ragged -offset indent +.Cd "device virtio" +.Cd "device virtio_pci" +.Ed +.Pp +Alternatively, to load VirtIO support as modules at boot time, place the +following lines in +.Xr loader.conf 5 : +.Bd -literal -offset indent +virtio_load="YES" +virtio_pci_load="YES" +.Ed +.Sh DESCRIPTION +VirtIO is a specification for para-virtualized I/O in a virtual machine (VM). +Traditionally, the hypervisor emulated real devices such as an Ethernet +interface or disk controller to provide the VM with I/O. +This emulation is often inefficient. +.Pp +VirtIO defines an interface for efficient I/O between the hypervisor and VM. +The +.Nm +module provides a shared memory transport called a virtqueue. +The +.Sy virtio_pci +device driver represents an emulated PCI device that the hypervisor makes +available to the VM. +This device provides the probing, configuration, and +interrupt notifications needed to interact with the hypervisor. +.Fx +supports the following VirtIO devices: +.Bl -hang -offset indent -width xxxxxxxx +.It Sy Ethernet +An emulated Ethernet device is provided by the +.Xr vtnet 4 +device driver. +.It Sy Block +An emulated disk controller is provided by the +.Xr virtio_blk 4 +device driver. +.It Sy Console +Provided by the +.Xr virtio_console 4 +driver. +.It Sy Entropy +Provided by the +.Xr virtio_random 4 +driver. +.It Sy Balloon +A pseudo-device to allow the VM to release memory back to the hypervisor is +provided by the +.Xr virtio_balloon 4 +device driver. +.It Sy GPU +Graphics support is provided by the +.Xr virtio_gpu 4 +device driver. +.It Sy SCSI +An emulated SCSI HBA is provided by the +.Xr virtio_scsi 4 +device driver. +.El +.Sh LOADER TUNABLES +Tunables can be set at the +.Xr loader 8 +prompt before booting the kernel or stored in +.Xr loader.conf 5 . +.Bl -tag -width "hw.virtio.pci.transitional" +.It Va hw.virtio.pci.disable_msix +If set to 1, disables MSI-X. +The default value is 0. +.It Va hw.virtio.pci.transitional +For a transitional +.Nm +device, this tunable specifies whether to negotiate +modern mode and use the modern +.Nm +driver +.Pq 1 +or to negotiate legacy mode and +use the legacy +.Nm +driver +.Pq 0 . +The default value is 1. +.El +.Sh SEE ALSO +.Xr virtio_balloon 4 , +.Xr virtio_blk 4 , +.Xr virtio_console 4 , +.Xr virtio_gpu 4 , +.Xr virtio_random 4 , +.Xr virtio_scsi 4 , +.Xr vtnet 4 +.Sh HISTORY +Support for VirtIO first appeared in +.Fx 9.0 . +.Sh AUTHORS +.An -nosplit +.Fx +support for VirtIO was first added by +.An Bryan Venteicher Aq Mt bryanv@FreeBSD.org . |